1. Technical Field
The invention relates to electric bulbs, particularly to bulbs using LED as a light source.
2. Related Art
Light emitting diodes have extensively applied in various lighting devices because of small volume, low power-consuming and great durability. A typical LED bulb, as shown in FIG. 1, is composed of a heat dissipating cup 10, a base 11, a cover 12, LED elements 13, a circuit board 14 and a power driver 15. The LED elements 13 are mounted on the circuit board 14. The power driver 15 is electrically connected between the base 11 and the circuit board 14 through wires 16, 17.
In such a LED bulb, the dissipating cup 10 and base 11 are integrally formed into a single piece. The connection between the power driver 15 and the circuit board 14 or the base 11 is undetachable. Thus, when the power driver 15 fails and requires to be replaced, the cover 12, circuit board 14 and power driver 15 must be disassembled first and then the wires 16, 17 have to be desoldered. It is very inconvenient for both users and manufactures because the failed bulbs cannot be repaired immediately.
A lifetime of LED elements can usually reach about 200,000 hours or above, while a lifetime of a power driver may only last about 30,000 hours. Thus, LED elements are longer than the power driver by almost seven times in lifetime. Thus, repair or replacement for the power driver within a lifetime of LED elements is unavoidable. However, conventional LED bulbs are very unadvantageous to maintenance of power drivers.